1. Field of the Invention
This invention relates to oil-soluble polymeric additives for fuel and lubricant; compositions, including concentrates, containing said additives and methods for their manufacture and use, wherein the polymeric additives are ionic polymers made by sulfonating an aliphatic hydrocarbon polyolefin polymer, which is neutralized with a metal compound. The polymeric additives are capable of imparting viscosity improvement, dispersancy, varnish inhibition, anti-rust and detergency properties.
Various polymers containing neutralized sulfonic acid groups are known in the additive art as follows.
U.S. Pat. No. 2,367,468 teaches metal, ammonia and amine salts of 500-3,000 molecular weight olefin copolymer reacted with chlorosulfonic acid to form a lubricant additive.
U.S. Pat. No. 2,677,702 forms a water-soluble sulfonated polymer wherein an olefin and a conjugated diene such as butadiene and isobutylene, are copolymerized and sulfonated to form polymers which can then be neutralized with metals, amines or alkanol amines, said polymers having molecular weights of about 1,000-6,000 and being useful in aqueous solutions and as emulsifiers.
U.S. Pat. No. 2,883,340 teaches V.I.-detergent additives for lubricating oil by sulfonating with SO.sub.3 or chlorosulfonic acid, a polymer of low molecular weight olefin, e.g. C.sub.3 to C.sub.6 olefins such as isobutylene, or copolymers such as butadiene-isoprene, of 10,000 to 50,000 molecular weight and then forming a metal salt.
U.S. Pat. No. 3,325,418 teaches high molecular weight polychlorosulfonated polymers which can be reacted with amines and are useful as V.I. improvers and as detergents in lubricating oils.
U.S. Pat. No. 3,352,782 reacts polymers having about 30-250 carbons and about 400-3,000 Staudinger molecular weight, which may have single or multiple unsaturations, such as polyisobutylene, with a chlorosulfonic acid.
U.S. Pat. No. 3,396,136 forms metal salts of polymeric sulfonic acid which polymers are prepared by polymerizing various monomers with an alkenyl aromatic sulfonic acid monomer, or by directly sulfonating polymers containing sulfonable aromatic groups and forming metal salts, to form a V.I. improver for lubricating oil.
U.S. Pat. No. 3,679,382 teaches a hydrocarbon fuel thickened with a polymeric material such as styrene copolymerized with an acrylate such as a sulfonic methacrylate.
U.S. Pat. No. 3,836,511 teaches a process for sulfonation of high molecular weight rubbers such as copolymers of ethylene, propylene and diene monomers, with an acyl sulfate prepared by mixing an anhydric monobasic acid such as acetic anhydride with sulfuric acid. Column 13 teaches that these materials may be reacted with any amine. Example 10 indicates that an avantage of the acyl sulfate is that it can be used without degradation of the polymer. However, there is no teaching of use in lubricating oil of the products thereby formed.
U.S. Pat. No. 3,931,021 teaches high molecular weight polymers, such as those of ethylene and other olefins, which are sulfonated and neutralized with a metal compound, following which polar cosolvent is used. The cosolvent may be an alcohol or an amine in relatively large amounts, e.g. 10-600 moles per molecular portion of the sulfonic acid moiety. The resulting material is taught as useful in lubricating oil as a V.I. improver.
U.S. Pat. No. 3,941,834 teaches polymers of 300-200,000 molecular weight of C.sub.2 -C.sub.6 unsaturated hydrocarbons which are reacted with chlorosulfonic acid and then reacted to form metal salts or amine compounds, with the amine compounds apparently reacting through the chlorine, which materials are useful multifunctional additives serving as V.I. improvers and detergents in lubricating oil.
U.S. Pat. No. 3,950,401 teaches sulfonation of low molecular weight polymers of 250-500 molecular weight prepared from propene or butene as lubricating oil anti-rust additives.
U.S. Pat. No. 4,086,171 teaches a block copolymer of a sulfonated monoalkenyl arene such as styrene, with an unsaturated olefin such as butadiene, said polymer being selectively hydrogenated and then sulfonated, and which can be reacted with ammonia or amines to form a V.I. detergent additive for lubricating oil.
U.K. Pat. No. 1,246,545 teaches dehydrohalogenating a chlorinated olefin polymer such as polyisobutylene of about 20 to 150 carbons, and then sulfonating and neutralizing with a metal base or amine to form a detergent additive for lubricating oil.